Table 1.

Binding constants for GPCR/compound interactions determined at 25 °C.

panela	A2AR* analytes	m.w. (Da)	ka (M−1s−1)	kd (s−1)	KD (nM)
3A	ZM-241,385	337	1.33(6) × 107,b	3.8(2) × 10−2,b	2.8(2)b
3B	PSB 36	386	5.1(6) × 106	3.6(4) × 10−2	7(1)
3C	XAC	428	1.39(2) × 106	1.12(1) × 10−2	8.1(1)
3D	SCH 442416	389	2.60(8) × 106	5.3(2) × 10−2	20.2(9)
3E	DPCPX	304	1.2(5) × 107	6(3) × 10−1	50(30)
3F	SCH 58261	345	1.00(3) × 106	6.6(2) × 10−2	66(1)
3G	MRS 1706	504	3.36(7) × 105	3.47(8) × 10−2	103(3)
3H	PSB 1115	388	3.9(1) × 105	3.18(9) × 10−1	810(30)
panel	β1AR* analytes	m.w. (Da)	ka (M−1s−1)	kd (s−1)	KD (nM)
3I	timolol	316	9.4(1) × 105	6.94(8) × 10−3	7.4(1)
3J	propranolol	259	4.5(1) × 105	3.28(4) × 10−3	7.2(2)
3K	alprenolol	249	1.31(4) × 106	2.49(7) × 10−2	19.0(1)
3L	nebivolol	405	2.76(5) × 105	1.50(3) × 10−2	31.8(1)
3M	labetalol	328	2.64(6) × 105	2.51(5) × 10−2	95(3)
3N	ICI 118,551	277	2.40(7) × 105	8.5(3) × 10−2	350(10)
3O	clenbuterol	277	2.47(9) × 105	1.33(5) × 10−1	540(30)
3P	L-748,337	498	2.37(6) × 105	1.41(4) × 10−1	600(20)
4A	butoxamine	267	---c	---c	5150(20)
4B	serotonin	176	---	---	14,170(50)
4C	atenolol	266	---	---	49,200(200)
4D	methylergonovine	339	---	---	49,600(300)
4E	ergonovine	325	---	---	84,100(800)

^akey to data sets shown in Figures 3 and 4.

^bnumber in parentheses is the standard error in the last digit

^cnot determined; K_D obtained from equilibrium analysis